The invention relates generally to welding systems, and, more particularly to welding power supplies with regulated background power supplies.
Many types of welding power supplies capable of providing a welding power output from an alternating current (AC) or a direct current (DC) source of power have been developed. Typically, such welding power supplies are configured to provide an average or rated power output for a welding process, such as a shielded metal arc welding (SMAW) operation. Unfortunately, during the welding operation, transient voltage requirements that may be equal to approximately two or three times the average or rated voltage level may be encountered. Such transient voltage requirements are typically of short duration (e.g., shorter than 1 msec) when compared to the overall welding time.
If a welding power supply is not capable of providing the transient voltage requirements in addition to the average load requirements, then an operator may observe undesirable effects, such as arc instability, arc outages, stubbing, improper welding, and so forth. Accordingly, welding power supplies capable of providing the average or rated load requirements as well as the transient high voltage requirements have been developed. For example, in some existing power supplies, the main inverter of an inverter-type power supply is designed to meet the dynamic requirements. However, such power supplies often have a higher transformer turns ratio, higher currents in the inverter switches, higher power losses, and so forth. Accordingly, there exists a need for improved power supplies capable of meeting the rated load requirements as well as the transient load requirements.